We first saw these at the Consumer Electronics show in Las Vegas, and was fascinated at the design.
It’s essentially a flat board with elastic straps criss-crossing, and rubber threading to help grip.
The layout of the straps has been arrived at through crazy algorithms, designed to determine max efficiency.
We now own about 5 and load them up for certain things.

On this unit we have: jambox, cables, plug extension block with USB charging receptacles, and an emergency radio (you never know)

This one has various cables, a battery block, and extra AC adaptor.

Point is, there are tons of ways to use these and various sizes. We just keep em loaded and ready to through in a bag or backpack.

Now they have a system for iPads/Tablets that cover the iPad and has a grid-it panel that gets covered.